Fiber-reinforced composite materials are used in many fields of sporting goods and equipment for leisure time amusement. One of the important characteristics of these sporting goods is lowness of elastic modulus, namely excellence in flexibility. For example, a flexible tennis racket prevents elbow pain, and a properly flexible fishing rod makes the hands smoothly feel a bite of fish and facilitates the taking-up of the fish. Also, in the case of a golf club, a club equipped with a shaft capable of holding flexibility is beneficial to amateurs and female golfers. Although their swing speed is slow, the use of such a club enables them to increase the head speed of the club so that a longer flying distance of ball is obtained because of the pliant suppleness of the shaft.
As stated above, in order to impart flexibility to a molded article produced from the fiber-reinforced composite material, a glass fiber or the like having a low tensile elastic modulus has been hitherto used. However, the use of a glass fiber is associated with disadvantages. For example, since the density of a glass fiber is larger than a carbon fiber or the like, the use of the glass fiber brings about increase in weight. Further, when a glass fiber and a carbon fiber are used in a combination, the difference in thermal expansivity between the two tends to cause defective products due to bending particularly in golf shafts, fishing rods, and the like.